【rust/esp32】初识slint ui框架并在st7789 lcd上显示

说在前面

• esp32版本：s3
• 运行环境：no-std
• 开发环境：wsl2
• LCD模块：ST7789V2 240*280 LCD
• Slint版本：master分支
• github地址：这里

关于slint

• 官网
• 为啥不用lvgl？
  只能说rust的生态还是不太行，lvgl的rust binding似乎还在开发中，已经有仓库了，但是还在开发中。
  slint目前比较完善，但是相关资料也少。
  反正已经在折腾rust了，也不在乎再多折腾个小众点的。

关于no-std

• 上一篇还是std环境，怎么就变成no-std了？
  std环境下也折腾了slint，但是fps就是不怎么高 （可能哪里写的不对） ，然后就试了下no-std，稍微丝滑点，并且编译也快。

关于dma

• rust生态下dma的资料更是少的可怜，找了好久也没啥进展，所以本文不涉及dma

准备工作

• 引脚连接见上篇
• 开发环境部分，由于不需要esp idf，简单很多，cargo直接搞定

相关依赖

• Cargo.toml

  [dependencies]
  hal = { package = "esp32s3-hal", version = "0.13.0"}
  esp-backtrace = { version = "0.9.0", features = ["esp32s3", "panic-handler", "exception-handler", "print-uart"] }
  esp-println = { version = "0.7.0", features = ["esp32s3","log"] }
  log = { version = "0.4.18" }
  esp-alloc = { version = "0.3.0" }
  embedded-hal = "0.2.7"
  embedded-graphics-core = "0.4.0"
  embedded-graphics = "0.8.1" 
  embedded-graphics-framebuf = "0.5.0"
  display-interface = "0.4"
  display-interface-spi = "0.4"
  mipidsi = "0.7.1"
  slint = { git = "https://githubfast.com/slint-ui/slint", default-features = false, features = ["compat-1-2","unsafe-single-threaded","libm", "renderer-software"] }[build-dependencies]
  slint-build = { git = "https://githubfast.com/slint-ui/slint" }
  

代码

#![no_std]
#![no_main]extern crate alloc;
use alloc::boxed::Box;
use alloc::rc::Rc;
use rs_esp32s3_no_std_st7789_demo::dma::DmaBackend;
use core::cell::RefCell;
use core::mem::MaybeUninit;
use display_interface_spi::SPIInterfaceNoCS;
use embedded_graphics_core::prelude::{DrawTarget, Point, RgbColor, Size};
use embedded_graphics_core::{pixelcolor::raw::RawU16, primitives::Rectangle};
use esp_backtrace as _;
use esp_println::println;
use hal::spi::master::{Spi, dma};
use hal::{clock::{ClockControl, CpuClock},peripherals::Peripherals,prelude::*,spi::SpiMode,systimer::SystemTimer,timer::TimerGroup,Delay, Rtc, IO,
};
use mipidsi::Display;#[global_allocator]
static ALLOCATOR: esp_alloc::EspHeap = esp_alloc::EspHeap::empty();// 分配内存
fn init_heap() {const HEAP_SIZE: usize = 250 * 1024;static mut HEAP: MaybeUninit<[u8; HEAP_SIZE]> = MaybeUninit::uninit();unsafe {ALLOCATOR.init(HEAP.as_mut_ptr() as *mut u8, HEAP_SIZE);}
}// slint自动编译ui代码
slint::include_modules!();
#[entry]
fn main() -> ! {init_heap();// slint 设置默认backendslint::platform::set_platform(Box::new(EspBackend::default())).expect("backend already initialized");let main_window = Recipe::new().unwrap();let strong = main_window.clone_strong();let timer = slint::Timer::default();// 由于我的lcd不支持触屏 这里模拟了下按钮点击timer.start(slint::TimerMode::Repeated,core::time::Duration::from_millis(1000),move || {if strong.get_counter() <= 0 {strong.set_counter(25);} else {strong.set_counter(0);}},);main_window.run().unwrap();panic!("The MCU demo should not quit");
}#[derive(Default)]
pub struct EspBackend {window: RefCell<Option<Rc<slint::platform::software_renderer::MinimalSoftwareWindow>>>,
}impl slint::platform::Platform for EspBackend {fn create_window_adapter(&self,) -> Result<Rc<dyn slint::platform::WindowAdapter>, slint::PlatformError> {let window = slint::platform::software_renderer::MinimalSoftwareWindow::new(slint::platform::software_renderer::RepaintBufferType::ReusedBuffer,);self.window.replace(Some(window.clone()));Ok(window)}fn duration_since_start(&self) -> core::time::Duration {core::time::Duration::from_millis(SystemTimer::now() / (SystemTimer::TICKS_PER_SECOND / 1000),)}fn run_event_loop(&self) -> Result<(), slint::PlatformError> {let peripherals = Peripherals::take();let mut system = peripherals.SYSTEM.split();let clocks = ClockControl::configure(system.clock_control, CpuClock::Clock240MHz).freeze();let mut rtc = Rtc::new(peripherals.RTC_CNTL);let timer_group0 = TimerGroup::new(peripherals.TIMG0, &clocks);let mut wdt0 = timer_group0.wdt;let timer_group1 = TimerGroup::new(peripherals.TIMG1, &clocks);let mut wdt1 = timer_group1.wdt;rtc.rwdt.disable();wdt0.disable();wdt1.disable();let mut delay = Delay::new(&clocks);let io = IO::new(peripherals.GPIO, peripherals.IO_MUX);let clk = io.pins.gpio18;let sdo = io.pins.gpio17;let cs = io.pins.gpio14;// 初始化spilet spi = Spi::new_no_miso(peripherals.SPI2,clk,sdo,cs,60u32.MHz(),SpiMode::Mode0,&clocks,);println!("spi init.");let dc = io.pins.gpio15.into_push_pull_output();let rst = io.pins.gpio16.into_push_pull_output();// spi interfacelet di = SPIInterfaceNoCS::new(spi, dc);// st7789 驱动let mut display = mipidsi::Builder::st7789(di).with_display_size(240, 280).with_window_offset_handler(|_| (0, 20)) // 这里稍微设置了下偏移.with_framebuffer_size(240, 280).with_invert_colors( mipidsi::ColorInversion::Inverted).init(&mut delay, Some(rst)).unwrap();println!("display init.");let mut bl = io.pins.gpio13.into_push_pull_output();bl.set_high().unwrap();let size = slint::PhysicalSize::new(240, 280);self.window.borrow().as_ref().unwrap().set_size(size);let mut buffer_provider = DrawBuffer {display,buffer: &mut [slint::platform::software_renderer::Rgb565Pixel::default(); 240],};loop {slint::platform::update_timers_and_animations();// 这里的大致流程是：// slint会计算出当前帧需要变化的像素// 结果会暂时存放在buffer_provider// 然后将buffer_provider中的数据传给spiif let Some(window) = self.window.borrow().clone() {window.draw_if_needed(|renderer| {renderer.render_by_line(&mut buffer_provider);});if window.has_active_animations() {continue;}}}}fn debug_log(&self, arguments: core::fmt::Arguments) {println!("{}", arguments);}
}struct DrawBuffer<'a, Display> {display: Display,buffer: &'a mut [slint::platform::software_renderer::Rgb565Pixel],
}impl<DI: display_interface::WriteOnlyDataCommand, RST: embedded_hal::digital::v2::OutputPin>slint::platform::software_renderer::LineBufferProviderfor &mut DrawBuffer<'_, Display<DI, mipidsi::models::ST7789, RST>>
{type TargetPixel = slint::platform::software_renderer::Rgb565Pixel;fn process_line(&mut self,line: usize,range: core::ops::Range<usize>,render_fn: impl FnOnce(&mut [slint::platform::software_renderer::Rgb565Pixel]),) {let buffer = &mut self.buffer[range.clone()];render_fn(buffer);// We send empty data just to get the device in the right windowself.display.set_pixels(range.start as u16,line as _,range.end as u16,line as u16,buffer.iter().map(|x| embedded_graphics_core::pixelcolor::raw::RawU16::new(x.0).into()),).unwrap();}
}

结果

• 还是有卡顿的感觉
  
• 对比c lvgl+dma，加权fps有157，差距太大了
  

参考

• slint mcu